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    <title>Document</title>
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        console.log(isNaN(123)); //数字，false
        console.log(isNaN("hello")); //非数字，true
        console.log(isNaN(4-1)); //数字，false
        console.log(isNaN(123)); //数字，false
        console.log(isNaN(-10)); //数字，false
        console.log(isNaN("123")); //数字，false
        console.log(isNaN("1a23")); //非数字，true

        var str="1+3";
        console.log(str); //1+3 +会被认为是一种字符符号而已 没有加法的作用
        console.log(eval(str)); //4 让字符串中的运算符号生效

        var name="拉勾网";
        console.log("转码前:"+name);
        name=encodeURI(name);
        console.log("转码后:"+name);
        name=decodeURI(name);
        console.log("解码后:"+name);


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